c语言怎样写积分程序,C语言实现定积分求解方法

求定积分的方法有很多种，下面是我总结的几种比较常用的方法。

#include

#include

#include

#include

#define N3

double fun(double x)

{

double y;

y = sqrt(4-(x)*(x));

//y = sin(x);

return y;

}

/*随机点法求定积分*/

double Darts(int n)

{

double x, y;

time_t t;

int i = 0;

int count = 0;

srand((unsigned)time(&t));

for (i=0; i

{

x = rand()%100/100.0;

y = rand()%100/100.0;

if (y <= 1-pow(x,2))

{

count++;

}

}

return (double)count/(double)n;

}

/*左矩形法求定积分*/

double LeftRect(double down, double up, int n)

{

double h, s;

int i;

/*计算步长*/

h = (up-down)/n;

s =